Installation Manual
ASCO 3ATS & 3NTS
Installation Manual
!
3ATS & 3NTS
E-design 260-400 A Transfer Switches
Rating Label
DANGER
DANGER is used in this manual to warn of a
hazard situation which, if not avoided, will result in
death or serious injury.
! WARNING
WARNING is used in this manual to warn of a
hazardous situation which, if not avoided, could
result death or serious injury.
!
CAUTION
Each transfer switch contains a rating label to define the loads
and fault circuit withstand/closing ratings. Refer to the label
on the transfer switch for specific values.
! WARNING
Do not exceed the values on the rating label.
Exceeding the rating can cause person injury or
serious equipment damage.
An experienced licensed electrician must install the transfer
switch.
CAUTION is used in this manual to warn of a
hazardous situation which, if not avoided, could
result in minor or moderate injury.
Refer
Refer to
to the
the outline
outline and
and wiring
wiring drawings
drawings provided
provided
with
the
3ATS
or
3NTS
for
all
installation
with the 3ATS or 3NATS for all installationand
and
connection
connection details
details and
and accessories.
accessories.
Refer to User’s Guide 381333-400 for the Group
G Controller status display messages, time delays,
pickup and dropout settings, and adjustments.
3ATS
The 3ATS is an automatic transfer switch. It includes transfer
test, generator start/stop control, and generator exerciser.
3NTS
The 3NTS is an electrically-operated manual transfer switch
(non-automatic). It does not include generator start/stop
control and generator exerciser.
Table of Contents
INSTALLATION
Mounting..........................................................2
Power Connections .........................................2
Engine Starting Contacts.................................3
FUNCTIONAL TEST
1- Manual Operation........................................3
2- Voltage Checks ...........................................4
3- Electrical Operation .....................................5
TESTING & SERVICE
Transfer Test ...................................................6
Preventive Maintenance ..................................6
Manual Load Transfer .....................................6
TROUBLESHOOTING ....................................7
INDEX..............................................................8
381333-403 A
381333-403 A
ASCO Power Technologies
Page 1
ASCO 3ATS & 3NTS
Installation Manual
Installation
NOTICE
These transfer switches are factory wired and tested.
Installation requires mounting, connecting service cables, and
connecting engine start and auxiliary control circuits (if
required.).
Supporting Foundation
The supporting foundation for the enclosure must be level and
straight. Refer to the applicable enclosure outline drawing
included with the transfer switch for all mounting details
including door opening space.
If bottom cable entry is used, the foundation must be prepared
so that the conduit stubs are located correctly. Refer to the
enclosure outline drawing for specified area and location.
Provide cable bending space and ½ inch minimum clearance
to live metal parts. When a concrete floor is poured, use
interlocking conduit spacer caps or a wood or metal template
to maintain proper conduit alignment.
Mounting
Refer to the outline and mounting diagram and mount the
transfer switch according to details and instructions shown on
the diagram. Mount it vertically to a rigid supporting
structure. Level all mounting points by using flat washers
behind the holes to avoid distortion of the transfer switch.
An insulator backing piece must be installed behind the
transfer switch. If the transfer switch is removed from the
enclosure and then reinstalled, this insulator piece must be
placed behind the transfer switch. See Figure 1.
! WARNING
Be sure that the insulator piece is behind the
transfer switch.
Insulator
backing
piece
Protect the transfer switch from construction grit
and metal chips to prevent malfunction or
shortened life of the transfer switch.
Line Connections
Refer to the wiring diagram provided with the transfer switch.
All wiring must be made in accordance with the National
Electrical Code and local codes.
!
DANGER
De-energize the conductors before making any line
or auxiliary circuit connections. Be sure that the
Normal and Emergency line connections are in
proper phase rotation. Place the engine generator
starting control in the OFF position. Make sure
engine generator is not in operation.
Testing Power Conductors
Do not connect the power conductors to the transfer switch
until they are tested. Installing power cables in conduit, cable
troughs, and ceiling-suspended hangers often requires
considerable force. The pulling of cables can damage
insulation and stretch or break the conductor’s strands. For
this reason, after the cables are pulled into position, and before
they are connected, they should be tested to verify that they
are not defective or have been damaged during installation.
Connecting Power Cables
After the power cables have been tested, connect them to the
appropriate terminal lugs on the transfer switch as shown on
the wiring diagram provided with the transfer switch. Make
sure that the lugs provided are suitable for use with the cables
being installed. Standard terminal lugs are solderless screw
type and will accept the wire sizes listed on the drawings
provided with the transfer switch. Be careful when stripping
insulation from the cables, avoid nicking or ringing the
conductor. Remove surface oxides from cables by cleaning
with a wire brush. When aluminum cable is used, apply joint
compound to conductors. Tighten cable lugs to the torque
specified on rating label.
Do not run cables behind the transfer switch. Cables can be
bundled on the right side. Maintain proper electrical clearance
between the live metal parts and grounded metal: ½ inch
minimum.
Figure 1. Required insulator backing piece.
Page 2
ASCO Power Technologies
381333-403 A
Installation Manual
ASCO 3ATS & 3NTS
Controller Ground
A grounding wire must be connected to the controller’s lower
left mounting stud. Because the controller is mounted on the
enclosure door, a conductive strap must be used between the
enclosure and the door. This connection provides proper
grounding which does not rely upon the door hinges.
Engine Starting Contacts
The engine control contact connections (if used) are located on
top of the transfer switch. Connect signal wires to appropriate
terminals as specified in Table A and shown in Figure 2.
Table A. Engine Start Connections.
When normal
source fails
Terminals on
transfer switch
contact closes
TB14 and TB15
contact opens
TB14 and TB16
Functional Test
The functional test consists of three checks: manual
operation, voltage checks, and electrical operation.
NOTICE
Do these checks in the order presented to avoid
damaging the transfer switch.
1 – Manual Operation
A detachable maintenance handle is provided on the transfer
switch for maintenance purposes only. Manual operation of
the transfer switch should be checked before it is energized
(operated electrically).
! WARNING
Do not manually operate the transfer switch until
both power sources are disconnected: open both
circuit breakers.
1. After deenergizing both power sources, open the enclosure
door. Locate the maintenance handle on the left side of the
transfer switch. Insert the maintenance handle into the
hole in the shaft, left side of the operator. See Figure 3
2. Move the maintenance handle up or down as shown to
manually operate the transfer switch. It should operate
smoothly without any binding. If it does not, check for
shipping damage or construction debris.
3. Return the transfer switch to the Normal position. Remove
the maintenance handle and store it on the left side.
not used
NOTICE
Verify that the maintenance handle has been
removed before proceeding!
Figure 2. Engine starting contact label
and location on the top of transfer switch.
Note: If Normal and Emergency connections are reversed this
operation is also reversed.
Harnesses
The transfer switch is connected to the left side of the
controller by a plug-in harness (two plugs).
Auxiliary Circuits
Connect auxiliary circuit wires to appropriate terminals on the
transfer switch as shown on the wiring diagram.
Read all instructions on the wiring diagram and labels affixed
to the transfer switch. Note the control features that are
provided and review their operation before proceeding.
hole
maintenance
handle
shaft
Figure 3. Maintenance handle and positions.
381333-403 A
ASCO Power Technologies
Page 3
ASCO 3ATS & 3NTS
Installation Manual
1
Close the normal source circuit breaker. The
normal source accepted and the load on normal
lights should come on.
Use an accurate voltmeter to
check phase to phase and
2 phase to neutral voltages
present at the transfer switch
normal source terminals.
3
Normal Source
Accepted
Load on
Normal
Load on
Emergency
Emergency
Source Accepted
Use an accurate voltmeter to
check phase to phase and
4 phase to neutral voltages
present at the transfer switch
emergency source terminals.*
Figure 4. Four indicator lights.
2 – Voltage Checks
First check the nameplate on the transfer switch; rated voltage
must be the same as normal and emergency line voltages.
!
Close the emergency source circuit breaker.
(Start generator, if necessary.) The emergency
source accepted light should come on.
DANGER
Use extreme caution when using a meter to
measure voltages in the following steps.
Do not touch power terminals; shock, burns, or
death could result!
Perform steps 1 through 6 at the right. Observe the indicator
lights. See Figure 4.
Use a phase rotation meter to
check phase rotation of
5 emergency source; it must be
the same at the normal
source.
Shut down the engine-generator, if applicable.
The emergency source accepted light should go
off. Then put the starting control selector switch
(on the generator set) in the automatic position.
6 Close the enclosure door.
● Black circle means the light is on.
○ White circle means the light is off.
* If necessary, adjust the voltage regulator on the generator
according to the manufacturer’s recommendations. The
transfer switch will respond only to the rated voltage specified
on the transfer switch nameplate.
Continue to 3 – Electrical Operation on the next page.
Also see User’s Guide 381333-400 for voltage settings in the
controller.
Page 4
ASCO Power Technologies
381333-403 A
Installation Manual
ASCO 3ATS & 3NTS
1
2
Observe
these
lights
Press this
button
Figure 5. Transfer button and indicator lights.
3 – Electrical Operation
This procedure will check the electrical operation of the
transfer switch.
The normal source must be available and the generator
must be ready to start. Check that the normal source
accepted light is on.
For 3ATS press the transfer button.
The engine should start and run
within 15 seconds. For 3NTS the
generator must be started manually
at the generator.
The emergency source accepted light should come on.
For 3ATS the transfer switch should transfer to the
emergency position. The load on emergency light
should come on and the load on normal light should go
off. For 3NTS press the transfer button for load transfer.
If the transfer to emergency delay
is used, the transfer occurs after a
3 time delay. For immediate transfer
(bypass timer) press the transfer
button again.
! WARNING
Close the transfer switch enclosure door and
tighten the screws before you test electrical
operation.
Perform steps 1 through 5 at the right. Observe the status
lights. See Figure 5.
● Black circle means light is on.
○ White circle means light is off.
NOTE: For 3NTS manually start the emergency generator at
the generator. Then press the transfer button for load transfer.
If the inphase transfer feature is activated, transfer may not
occur immediately. Transfer will occur when the phase
relationship between sources is correct. Press the transfer
button again for load retransfer to normal, then manually stop
the generator at the generator.
For 3ATS the transfer switch should transfer back to the
normal position. The load on normal light should come
on and the load on emergency light should go off.
For 3NTS press the transfer button for load retransfer.
If the retransfer to normal delay is
used the retransfer should occur
4 after a time delay. For immediate
retransfer (bypass timer) press the
transfer button again.
For 3ATS the unloaded running delay keeps the
generator running for a cool-down period. Then the
generator should stop and the emergency source
accepted light should go off. For 3NTS manually stop
5 the generator at the generator (after a cool-down period).
Also see User’s Guide 381333-400 for inphase transfer and
time delay settings in the controller.
This completes the functional test of the transfer switch.
Leave the engine-generator starting control in the automatic
position.
381333-403 A
ASCO Power Technologies
Page 5
ASCO 3ATS & 3NTS
Installation Manual
Testing & Service
Replacement Parts
Transfer Test
Operate the transfer switch at least once a month by following
the Electrical Operation procedure on page 5.
When ordering replacement parts provide the Serial No., Bill
of Material No. (BOM), and Catalog No. from the transfer
switch nameplate. In the US call 800-800-2726 (ASCO) or
contact customercare@asco.com.
Preventive Maintenance
Manual Load Transfer
Reasonable care in preventive maintenance will insure high
reliability and long life for the transfer switch. An annual
preventive maintenance program is recommended.
This procedure will manually transfer the load if the controller
is disconnected.
! WARNING
ASCO Services, Inc. (ASI) is ASCO Power
Technologies’ national service organization.
ASI can be contacted at 1-800-800-2726 for
information on preventive maintenance agreements.
Yearly Inspection
!
DANGER
Hazardous voltage capable of causing shock,
burns, or death is used in this transfer switch.
Deenergize both Normal & Emergency power
sources before performing inspections!
Do not manually operate the transfer switch until
both power sources are disconnected: open both
circuit breakers.
1. Deenergize both the normal and emergency source (open
both circuit breakers).
2. Use the maintenance handle to manually operate the
transfer switch to the opposite source. See page 4, Manual
Operation.
3. Close the enclosure door. If the transfer switch is in the
emergency position, manually start the generator and then
close the emergency source circuit breaker.
Clean the enclosure. Deenergize all sources, then brush
and vacuum away any excessive dust accumulation. Remove
moisture with a clean cloth.
Inspect the transfer switch contacts. Deenergize all
sources, then remove the transfer switch barriers and check the
contact condition. Replace contacts when pitted or worn
excessively. Reinstall the barriers carefully.
Maintain transfer switch lubrication. Under normal
operating conditions no further lubricating is required. Renew
factory lubrication if the transfer switch is subjected to severe
dust, abnormal operating conditions, or if the TS coil is
replaced. Order lubrication kit 75-100.
Check all cable connections & retighten them.
Torque to values shown on the transfer switch label.
Page 6
ASCO Power Technologies
381333-403 A
Installation Manual
ASCO 3ATS & 3NTS
Troubleshooting
Check in Numerical Sequence
Problem
1
Operation
2
Generator
3
Voltage
For 3ATS the generator set does
not start when the transfer button
is pressed or when the normal
source fails.
The outage must be long
enough to allow for the
feature 1C time delay
plus engine cranking and
starting time.
Starting control must be in
automatic position.
Batteries must be
charged and connected.
Check wiring to the
engine starting contacts.
-
For 3ATS the transfer switch does
not transfer the load to the
emergency source after the
generator starts.
Wait for the feature 2B
time delay. For
immediate transfer,
press the transfer button
(bypass timer). If
inphase transfer is
active, wait for inphase
condition. For 3NTS
press the transfer button.
Is the emergency source
accepted light on?
Generator output circuit
breaker must be closed.
Generator frequency must
be correct.
Voltmeter should read at least
90% of nominal phase to
phase voltage between
transfer switch terminals EA
and EC (or EL1 and EL2 for 2
pole switches). *
* These are factory settings.
For 3ATS the transfer switch does
not transfer the load to normal
source when normal returns or
after transfer test.
Wait for the feature 3A
time delay. For
immediate retransfer,
press the transfer button
(bypass timer). If
inphase transfer is
active, wait for inphase
condition. For 3NTS
press the transfer button.
-
Voltmeter should read at least
90% of nominal phase to
phase voltage between
transfer switch terminals NB
and NC, NC and NA, and NA
and NB (or NL1 and NL2 for 2
pole switches). *
* These are factory settings.
For 3ATS the generator does not
stop after load retransfer to the
normal source.
Wait for the feature 2E
time delay.
Starting control must be in
automatic position.
-
For 3NTS this light is
always on, indicating it is
a manual transfer switch.
-
-
Read the display for
more information.
Refer to User’s Guide
381333-400.
-
-
Not in auto light is always on.
Alert light is on.
381333-403 A
ASCO Power Technologies
Page 7
ASCO 3ATS & 3NTS
Installation Manual
INDEX
A
alert light, 7
see User’s Guide 381333-400
ASI is ASCO Services Inc.
800-800-2726(ASCO)
customercare@asco.com
automatic operation, 3ATS, 5
auxiliary circuits, 3
B
battery, 7
C
cables, power, 2
connections, 2, 3
controller
see User’s Guide 381333-400
controller ground, 3
cooldown, generator, 5, 7
D
DANGER statements, 1, 2, 4, 6
E
electrical operation, 5
emergency source accepted light,
4, 5
engine starting contacts, 3
F
foundation, 2
frequency, 7
functional test, 3
G
generator, 3, 4, 5, 7
ground, controller, 3
H
harness, 3
HELP 800-800-2726(ASCO)
customercare@asco.com
Printed in U.S.A.
Page 8
I
inphase transfer feature, 5, 7
inspection, 6
installation, 2
insulator backing piece, 2
WARNING, 2
L
lights, 4, 5, 7
line connections, 2
load on emergency light, 4, 5
load on normal light, 4, 5
lubrication, 6
M
maintenance, 6
maintenance handle, 3, 6
WARNING, 3, 6
manual load transfer, 6
WARNING, 3, 6
manual operation, 3
WARNING, 3, 6
manual transfer, 3NTS, 5
membrane controls, 4, 5
mounting, 2
S
source acceptable lights, 4, 5
starting contacts, 3
starting control, 7
starting problem, 4, 7
stopping problem, 7
T
terminals, 2, 3
testing power conductors, 2
time delays, 5, 7
transfer button, 5, 7
transfer problem, 7
troubleshooting, 7
V
voltage checks, 4, 7
W
WARNING statements, 1, 3, 5, 6
N
non-automatic 3NTS, 5, 7
normal source accepted light, 4, 5
not in auto light, 7
O
operation, electrical, 5
P
phase rotation, 4
preventive maintenance, 6
problem, 7
R
rating label, 1
replacement parts, 6
retransfer button, 5, 7
© ASCO Power Technologies, L.P. 2013
ASCO Power Technologies
381333-403 A